Observations of modulated shock waves in solid targets driven by spatially modulated laser beams

The growth of surface perturbations due to nonuniformities in the drive laser is an important subject in laser–matter interactions. We present results of experiments using drive lasers with known, single-mode modulations to produce nonuniform shocks that propagate into planar plastic (CH) targets. An optical probe beam is used to measure the arrival of these modulated shocks at various surfaces in the target. Experiments at moderate laser intensities (≲1013 W/cm2) exhibit behavior predicted by hydrocodes and simple scaling laws. This technique will be used to observe various dynamic effects in laser-produced plasmas and shock-wave propagation.